1. Field of the Invention
This invention relates to telephone answering devices, and more particularly to a system of telephone answering devices that are able to uniquely and interactively access a single telephone line shared between them with enhanced operating features.
2. Description of the Related Art Including Information Disclosed Under 37 C.F.R. .sctn..sctn. 1.97-1.99
Telephone answering devices (TADs) began replacing operator exchanges for answering telephones with the increased presence of consumer electronics in the open marketplace. Since the 1960's, the number of TADs has increased significantly, especially in homes and residences.
Previously, only a single TAD would be connected to a single telephone line as there was no way to allow the single telephone line to be shared between two TADs. If two TADs were connected to the same telephone line, the two TADs would independently answer an incoming telephone call. Both might simultaneously play back their outgoing greeting messages to the caller, and then both would simultaneously record the caller's incoming message. The problems with such an arrangement are obvious. The caller may be confused and there is no way the caller can maintain the privacy of the call by having it recorded by only one of the TADs.
One solution to this problem is to have a single telephone line for each individual. In this way, privacy is maintained for a caller's incoming message as the caller must direct the call by entering a specific telephone number. This solution has several disadvantages due to the significant cost to install individual lines, the wiring requirements inside any established building, and the caller must recall the number for each of the several persons associated with each of the several telephones. Furthermore, a telephone answering device (TAD) must be purchased for each line, such a telephone answering device costing an additional significant amount.
In order to overcome some of these problems, a system was developed that allowed several individuals to share the same telephone line and to keep private all the incoming telephone messages. U.S. patent application Ser. No. 07/671,504, filed on Mar. 19, 1991 by Becker and Mayer entitled SHARED LINE TELEPHONE ANSWERING DEVICE sets forth such a system and is incorporated herein by this reference.
In the Becker and Mayer device, a regular TAD may act as a central or master TAD (MTAD) while a number of modified extension TADs (ETADs) are connected to and share the same telephone line as the MTAD. When an incoming call is answered by the MTAD, the caller can be instructed as to the available options for leaving a message upon the MTAD or one of the ETADs. The default response of the system is for the caller to leave a message on the MTAD. In this way, even if the caller does not understand the instructions, the call is not lost. The caller may intentionally choose to leave a message on the MTAD without leaving a message on any of the ETADs. If so, the MTAD acts as a typical TAD by greeting the caller with a pre-recorded message, recording the caller's message, and then resetting itself to receive the next call.
If the caller should choose to leave a message on one of the ETADs sharing the telephone line, the caller selects the specific ETAD by transmitting one or more of the tones associated with one of the keypad buttons on pushbutton (i.e., touch tone) telephones. Each of the ETADs has a unique specifying tone code that activates the ETAD when its code is received. In order to prevent both an activated ETAD and the MTAD from recording the caller's message, the code (or at least part of it, such as a prefix) which activates the chosen ETAD also serves to temporarily disconnect the MTAD from the telephone line. A disconnect module connected between the MTAD and the telephone line recognizes tone codes transmitted by the caller so that it can temporarily disconnect the MTAD from the shared telephone line.
With the Becker and Mayer MTAD/ETAD system, a family or business can have several TADs independently and separately capable of storing messages intended for a specific party or person. Not only does the system promote proper routing of a message to a person, but it also promotes privacy. Each party has an individual TAD connected to the shared telephone line, yet each party has the same privacy as if each individual TAD were connected to its own telephone line. Further, this individual privacy does not require the additional cost of separate lines.
The MTAD/ETAD system presents advantages over previous telephone answering device systems and further advancements have been made that enhance the operation of the system, making it more attractive to the ultimate consumer by expanding the capabilities of the system. Further, certain areas of operation which had previously presented problems have been addressed to increase the convenience and utility of the system.